It has a monster 600+ PIN BGA (ball grid array) LSI chip on it (LSISAS1078). I'm sure there are a few XOR's in there somewhere.
http://www.lsilogic.com/news/product_news/2005_03_23.html LSI Logic First to Validate Serial Attached SCSI (SAS) RAID-On-Chip/RAID Stack Solution LSISAS1078 SAS RAID-on-Chip (ROC) being tested with two industry-leading RAID stacks and RAID 6 Lab testing demonstrates highly integrated, single-chip SAS ROC solution that reduces board real estate requirements and provides a value segment solution MegaRAID(r) software stack provides advanced data protection ideal for enterprise servers and external storage Fusion-MPT(tm) (Message Passing Technology) architecture speeds development of third-generation ROC product to the industry's broadest Serial Attached SCSI product line Maybe they put a software limit in the drivers when you are running SATA drives instead of SAS to slow you down on purpose. Tom -----Original Message----- From: Ben Scott [mailto:mailvor...@gmail.com] Sent: Tuesday, February 24, 2009 4:04 PM To: NT System Admin Issues Subject: Re: HP RAID5 P400 SATA questions On Tue, Feb 24, 2009 at 3:52 PM, Alverson, Tom (Xetron) <tom.alver...@ngc.com> wrote: > The P800 ... is "the highest performing controller > in the SAS portfolio" Does it have dedicated silicon for XOR? That's what matters. This might be called an "XOR engine" or "XOR co-processor" or "RAID-5 accelerator" or something along those lines. In this past, it was always a separate ASIC, although these days, I wouldn't be surprised to find that microprocessors with a built-in XOR vector engine are available. > ... "supports over 100 hard drives" ... How many drives it can support has little-to-nothing to do with RAID performance. That's more about the actual SAS/SATA interface controller chip. The RAID part is almost always implemented as one or more chips separate from the actual disk interface. (As a good design practice, a controller that can support more drives should have more computational ability to go with it, but if they're quoting 100+ drives they're obviously talking theory, not real-world performance, so I wouldn't bet on that.) -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
